There was a big war where the Akatsuki member Tobi resurrected every famous dead ninja so that he could take over the world. It turned out that Tobi was actually the legendary shinobi Uchiha Madara, one-time friend and rival of the first Hokage. *Then* it turned out that Madara was actually Obito, Kakashi's friend who gave Kakashi his sharingan eye just before he seemingly died. Obito didn't actually die, though; he was rescued and nursed back to health by the actual Madara Uchiha, who had a diabolical scheme to capture all the tailed beasts and combine them into one powerful chakra monster: Ten Tails. Obito, for his part, wants revenge against an unjust world that allowed his friend Rin to die.
There are a bunch of battles. Shikamaru and Ino's dads die. Guy fights against Madara and almost dies, but then he gets saved. It's the rare moment where one of the side characters gets to do something cool. Sasuke decides to come back and help out. At this point, Sasuke is monstrously powerful. Obito eventually turns good and helps the heroes to fight against Madara and Ten Tails. It turns out that Madara and Hashirama, the First Hokage, are reincarnations of the Sage of Six Path's two sons - one aggressive and violent, the other more gentle and kind. Naruto and Sasuke are also reincarnations of the Sage's sons.
Out of nowhere - seriously, it's random as hell - Kaguya, the Sage of Six Path's evil mother, shows up and causes a ruckus. Almost everyone on the planet gets trapped in an evil chakra tree. Naruto and Sasuke don't get trapped, so they team up and defeat Kaguya.
After Kaguya is defeated, Sasuke decides that it's time to be a jerk. He and Naruto fight, but they exhaust their energy and Sasuke concedes defeat.
Flash forward many years - Kakashi was 6th hokage but he's retired, so Naruto has become the 7th hokage. Naruto and Hinata are married and have a son named Boruto. Sasuke and Sakura have a daughter, but Sasuke is rarely home - he's always out on some mission or other.
